Work vehicles such as a hydraulic excavator are required to achieve both of low fuel consumption and improved workability.
For example, Japanese Patent Laying-Open No. 2012-241585 (PTD 1) discloses an example of a work vehicle capable of achieving both of low fuel consumption and improved workability as described above. Specifically, this PTD discloses an engine controlling apparatus including: detection unit; no-load maximum rotation speed calculation means; target matching rotation speed calculation means; engine target output calculation means; and engine control means.
The detection means detects the operation state of the work machine. Based on the operation state, the no-load maximum rotation speed calculation means calculates the no-load maximum rotation speed corresponding to the rotation speed of the engine that is increased to the maximum level when the load for the work machine is released. Based on the operation state, the target matching rotation speed calculation means calculates, separately from the no-load maximum rotation speed, the target matching rotation speed corresponding to the rotation speed of the engine that is increased when a load is applied to the work machine. Based on the operation state, the engine target output calculation means calculates an engine target output that can be output to the utmost extent. The engine control means controls the engine rotation speed to fall within a range between the no-load maximum rotation speed and the target matching rotation speed in the state where the engine target output is limited.